Method for producing charge control agent and toner

ABSTRACT

A method for producing a charge control agent or a toner containing the charge control agent comprising reacting in aqueous medium an azo compound with a salicylic acid chromium complex.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. §119 and the Paris Convention Treaty, this application claims the benefit of Chinese Patent Application No. 200810197365.2 filed Oct. 23, 2008, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for producing charge control agent and a toner containing such charge control agent.

2. Description of the Related Art

In the past, the charge control agent formed by azo metal complex is wildly used in various fields composed of the field in which the developer toner is used for forming electrophotography; the charge control agent is used as one of the formation materials of the toner (for example: Japanese patent publication No. 63-61347 bulletin, Japanese patent publication No. 2-16916 bulletin, Japanese patent publication No. 2002-53539 bulletin and patent No. 2531957 bulletin). Especially in recent years, along with the expansion of the utilization function of the electrophotography, the charge control agent unfolds the application in the light printing field and is applied to the light printing field as the formation material of the toner.

In the light printing field, the printing speed is required to be faster; in addition, in the printing field including the light printing field, what is evaluated is not the printing process itself, but printed images, that is, the prints. Therefore, in the so-called printing field, the formed image-hard copy is required to be an image with stable picture quality for a long time.

However, in order to ensure the formed image to get stability when the printing is in a high speed, the developer is required to mix and electrify the newly recharged toner in a short time. Along with the high speed orientation of the printing, the recharge rate of the toner is also in a high speed; however, if the toner has insufficient electrification property, the toner which is used as the developer has insufficient electrification performance, and the charge of the toner is not uniform; the insufficiently electrified toner can cause the problems of toner flying, fog, etc.

Additionally, when the developer is used for a long time, the variation of the using environment of an image formation device can change the electrification performance of the toner which is used as the developer; subsequently, the obtained images, especially all-black or half-tone images, can have the problems of variation in concentration.

On the other hand, the method for producing charge control agent formed by the azo metal complex wildly adopts the method of taking an azo compound as the raw material to synthesize the metal complex. As the charge control agent obtained by the method can not completely remove a complexing agent and reaction medium used for synthesizing the complexation of the azo metal complex, residual components can exist. In order to synthesize the azo metal complex, chromic formate is ordinarily used as the complexing agent; additionally, the reaction medium generally adopts ethylene glycol monoethyl ether, ethylene glycol monomethyl ether and other organic solvents; as the chromic formate can generate formic acid having bigger irritation to skin, and the ethylene glycol monoethyl ether and the ethylene glycol monomethyl ether is doubted as hazardous chemicals substances, therefore, from the point of view of safety, the method for producing charge control agent formed by the azo metal complex without the ethylene glycol monoethyl ether and the ethylene glycol monomethyl ether is especially required to be developed as soon as possible.

SUMMARY OF THE INVENTION

Based on the background, the invention researches the method for producing charge control agent formed by the azo metal complex and further researches the electrification property and other electrification control performance of the charge control agent, and finds that in the manufacturing engineering, the residual components of the reaction medium used in the synthesis of the azo metal complex has great influence to the electrification performance, thus finishing the invention.

In view of the above-described problems, it is one objective of the invention to provide a method for producing charge control agent. Even the reaction medium of the reaction system for obtaining the azo chromium complex has residual components, the residual components can not bring disadvantages to the electric regulator. Therefore, the producing method of the invention can simply obtain the charge control agent.

Another objective of the invention is to provide a method for producing charge control agent with excellent electrification control performance.

Again another objective of the invention is to provide a toner with excellent electrification property, which can not cause flying or fog even in the occasion of forming image in a high printing speed; the toner is also free from the influences of using environmental variation composed of temperature and humidity and ensures to stably obtain images with long-term high picture quality.

The method for producing charge control agent is a producing method for obtaining the charge control agent formed by the azo chromium complex, which is characterized in that, in an aqueous medium, the azo chromium complex indicated by the following general formula (1) is synthesized through the reaction of an azo compound and a salicylic acid chromium complex which is used as a complexing agent.

In the formula, R¹ to R⁴ respectively indicate hydrogen atoms, the alkyl having 1-18 carbon atoms with or without permutation groups, the alkenyl with 1-18 carbon atoms, the alkoxy with 1-18 carbon atoms, sulfonic group, Methyl sulfonyl, sulfoacid amino, the alkyl amino sulfonyl with 1-18 carbon atoms, hydroxyl, carboxyl, —COOR⁵ group (wherein, R⁵ indicates the alkyl with 1-18 carbon atoms), acetylamino, bromine atoms, chlorine atoms, iodine atoms, fluorine atoms and nitryl. Z¹ and Z² respectively and independently indicate hydrogen atoms, carboxyl, hydroxyl, —COOR⁶ group (wherein, R⁶ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.), —CONHR⁷ (wherein, R⁷ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.), and —NHCOR⁸ (wherein, R⁸ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.); additionally, Am+ indicates cations with 1-6 valents; m indicates an integer between 1 and 6, n¹-n⁴ indicate integers between 0 and 4 (requiring to meet the condition that n¹+n²=4 and n³+n⁴=4.).

In the method for producing charge control agent, the salicylic acid chromium complex forming the complexing agent preferably adopts chromium salicylic acid alkali metal salt.

In the method for producing charge control agent and in the synthesis engineering of a complex, the reaction between the azo compound and the salicylic acid chromium complex which is used as the complexing agent is preferably carried out with the existence of the selected compounds from the group composed of long-chain alkyl ammonium salt, aryl ammonium salt and crown ether or strong polar solvents and inorganic base compounds.

In the method for producing charge control agent, the azo compound is obtained through the coupling reaction and synthesis of an aromatic diazo compound and a naphtholate compound, and the salicylic acid chromium complex is preferably added into the reaction solution of the coupling reaction as the complexing agent.

A toner of the invention contains the charge control agent obtained from the above method for producing charge control agent.

According to the method for producing charge control agent of the invention, in the reaction system of the azo compound and the complexing agent for obtaining the azo chromium complex, the reaction medium selectively uses the aqueous medium, even the reaction medium used in the synthesis engineering for the azo chromium complex can not be completely removed and leaves residual components, no disadvantages are brought by the residual components of the reaction medium; moreover, owning to the combination of hydrogen of the water in the aqueous medium that forms the reaction medium, the characteristics of the azo chromium complex can be developed, thereby obtaining the charge control agent with excellent electrification control performance.

In the method for producing the charge control agent, when the complex of the coupling reaction of the aromatic diazo compound and the naphtholate compound is used, the azo compound which is used as the raw material of the azo chromium complex needs not to recycle the azo chromium complex of the target reaction resultant in the obtained reaction solution; instead, the complexing agent is added into the reaction solution; therefore, the reaction system for synthesizing the azo chromium complex is formed and the charge control agent is easily obtained.

Additionally, in the method for producing charge control agent, the reaction of the azo compound and the complexing agent is carried out with the existence of the selected compounds from the group formed by the long-chain alkyl ammonium salt, the aryl ammonium salt and the crown ether or the strong polar solvents and the inorganic base compounds. On one hand, the reaction of the complex can be easily carried out; on the other hand, the electrification property can be stabilized, thus easily producing the charge control agent with excellent electrification control performance.

As the toner of the invention contains the charge control agent with excellent electrification control performance, the image with high picture quality can be obtained without the influence of the using environment; additionally, even the image is formed in a high printing speed, owing to the excellent electrification property, the flying of the toner and the fog caused by uneven charge of the toner will not occur, thus obtaining the image with high picture quality.

The following is the detailed description of the invention.

The method for producing an charge aims at acquiring the charge control agent formed by the azo chromium complex (which is called ‘specific azo chromium complex’ in the following) indicated in the general formula (1), which comprises complex synthesis engineering (which is called ‘specific complex synthesis engineering’ in the following) and the specific content is: in the aqueous medium, the azo compound (which is called ‘material azo compound’ in the following) is reacted with the salicylic acid chromium complex which is used as the complexing agent so as to synthesize the specific zao chromium complex.

Here, the ‘aqueous medium’ is formed by the principal component water, specifically speaking, the containing proportion of the water is required to be more than 50% by weight, most preferably over 80% by weight.

In the general formula (1) which indicates the specific azo chromium complex, R¹ to R⁴ respectively and independently indicate hydrogen atoms, alkyl having 1-18 carbon atoms with or without permutation groups, the alkenyl with 1-18 carbon atoms, the alkoxy with 1-18 carbon atoms, the sulfonic group, the Methyl sulfonyl, the sulfoacid amino, the alkyl amino sulfonyl with 1-18 carbon atoms, the hydroxyl, the carboxyl, the —COOR⁵ group (wherein, R⁵ indicates the alkyl with 1-18 carbon atoms), the acetylamino, the bromine atoms, the chlorine atoms, the iodine atoms, the fluorine atoms and the nitryl.

The R¹ to R⁴ can be identical or not.

Group R¹ to group R⁴ indicate the alkyl having 1-18 carbon atoms with or without permutation groups, such as methyl, capryl, decyl, dodecyl, 2-ethylhexyl, t-dodecyl, etc.

Group R¹ to group R⁴ indicate the alkenyl with 2-18 carbon atoms, such as dodecenyl, octenyl, etc.

Group R¹ to group R indicate the alkoxy with 1-18 carbon atoms, such as CH₃O-group, C₂H₅O-group, C₈H₁₇O-group, C₁₂H₂₅O-group, C₁₅H₃₁O-group, etc.

Group R¹ to group R⁴ indicate sulfonic group, such as —SO₃H group.

Group R¹ to group R⁴ indicate the alkyl amino sulfonyl with 1-18 carbon atoms, such as CH₃NHSO₃-group, (CH₃)₂NSO₃-group, (C₂H₅)₂NSO₃-group, (C₈H₁₇)₂NSO₃-group, (C₁₂H₂₅)₂NSO₃-group, etc.

Group R¹ to group R⁴ indicate —COO R⁵ group, such as CH₃COO-group, C₂H₅COO-group, C₃H₇COO-group, C₄H₉COO-group, C₈H₁₇COO-group, C₁₂H₂₅COO-group, C₁₅H₃₁COO-group, etc.

Additionally, in the general formula (1), Z¹ and Z² respectively and independently indicate the hydrogen atoms, the carboxyl, the hydroxyl, —COOR⁶ group (wherein, R⁶ indicates the phenyl with or without permutation atoms, the alkyl having 1-18 carbon atoms with or without permutation atoms and the cycloalkyl having 3-12 carbon atoms with or without permutation atoms.), —CONHR⁷ group (wherein, R⁷ indicates the phenyl with or without permutation atoms, the alkyl having 1-18 carbon atoms with or without permutation atoms and the cycloalkyl having 3-12 carbon atoms with or without permutation atoms.), and —NHCOR⁸ group (wherein, R⁸ indicates the phenyl with or without permutation atoms, the alkyl having 1-18 carbon atoms with or without permutation atoms and the cycloalkyl having 3-12 carbon atoms with or without permutation atoms.).

Z¹ and Z² can be identical or not.

Group Z¹ and group Z² indicate —COOR⁶ group, such as CH₃COO-group, C₂H₅COO -group, C₃H₇COO-group, C₄H₉COO-group, C₈H₁₇COO-group, C₁₂H₂₅COO-group, C₁₅H₃₁COO-group, etc.

Group Z¹ and group Z² indicate —CONHR⁷ group, such as —CONHC₆H₅ group, —CONH(Cl)C₆H₄ group, —CONH(CH₃O)₂C₆H₃ group, —CONH(NO₂)C₆H₄ group, —CONH(CH₃)(Cl)C₆H₃ group, —CONH(CH₃O)₂(Cl)C₆H₂ group, —CONH((CH₃)₂CH)₂C₆H₃ group, —CONH(C₃H₇)C₆H₄ group, —CONH(C₈H₁₇)C₆H₄ group, —CONH(C₁₂H₂₅)C₆H₄ group, —CONH(C₁₈H₃₇)C₆H₄ group, —CONH((C₈H₁₇O)C₃H₄)C₆H₄ group, —CONH(C₃H₅)C₆H₄ group, —CONH(C₁₂H₂₃)C₆H₄ group, etc.

Group Z¹ and group Z² indicate —NHCOR8 group, such as —NHCOCH3 group, —NHCOC₈H₁₇ group, etc.

Additionally, in the general formula (1), A^(m+) indicates the cations with 1 to 6 valents, m indicates an integer between 1 and 6.

Here, the cations indicated by A^(m|) can be both inorganic cations and inorganic cations.

In the general formula (1), A^(m+) indicates inorganic cations, such as H⁺, K⁺, Li⁺, Na⁺, Ca²⁺, Mg²⁺, Ba²⁺, SR²⁻, Zn²⁺, Cu²⁺, CO²⁺, Ti²⁺, Fe²⁺, Mn²⁺, Ni²⁺, Sn²⁺, Si²⁺, Al³⁻, Cr³⁺, Fe³⁺, Co³⁺, Si⁴⁺, Te⁴⁺, Ti⁴⁺, Zr⁴⁺, Ge⁴⁻, NH⁴⁺, W⁵⁺, MO⁵⁻, W⁶⁺, MO⁶⁺, etc. and organic cations, such as (H₃NCH₂CH₂CH₂NH₃)²⁺, (H₁₇C₈HNCH₂CH₂CH₂NH₃)²⁺, (H₃₃C₁₆HCOHCH₂NH₂CH₂CH₂NH₃)²⁺, (H₂₉C₁₄HCOHCH₂HNC₂H₅CH₂CH₂NH₂C₂H₅)²⁺, (H₃NCH₂CH₂CH₂NH₂CH₂CH₂CH₂NH₃)³⁺, (H₅C₂HNC₂H₅CH₂CH₂CH₂HNC₂H₅CH₂CH₂CH₂HNC₂H₅C₂H₅)³⁺, (H₃NCH₂CH₂CH₂N(CH₃)₂CH₂CH₂CH₂N(CH₃)₂CH₃)³⁺, (H₃NCH₂CH₂CH₂NH₂CH₂CH₂CH₂NH₂CH₂CH₂CH₂NH₃)⁴⁺, (H₂N(C₂H₅)CH₂CH₂CH₂N(C₂H₅)₂CH₂CH₂CH₂N(C₂H₅)₂CH₂CH₂CH₂N(C₂H₅)₂CH₂CH₂CH₂NH₃)⁵⁺, (H₃CHNCH₃CH₂CH₂N(C₂H₅)₂CH₂CH₂N(C₂H₅)₂CH₂CH₂N(C₂H₅)₂CH₂CH₂N(C₂H₅)₂CH₂CH₂HNCH₃CH₃)⁶⁺, etc.

Additionally, in the general formula (1), n1 to n4 respectively indicate an integer between 0 to 4 and are required to meet the conditions of n¹+n²=4 and n³+n⁴=4.

The specific azo chromium complex is a better example, just as the azo chromium complex indicated in the general formula (2).

The specific azo chromium complex indicated by the general formula (2) is a substance having n¹-n⁴ adopted 1 and m adopted 1 in the general formula (1).

In the formula, R⁸ and R⁹ respectively and independently indicate the hydrogen atoms, alkyl having 1-18 carbon atoms with or without permutation groups, the alkenyl with 2-18 carbon atoms, the alkoxy with 1-18 carbon atoms, the sulfonic group, the Methyl sulfonyl, the sulfoacid amino, the alkyl amino sulfonyl with 1-18 carbon atoms, the hydroxyl, the carboxyl, the —COOR⁵ group (wherein, R⁵ indicates the alkyl with 1-18 carbon atoms), the acetylamino, the bromine atoms, the chlorine atoms, the iodine atoms, the fluorine atoms and the nitryl.

Z³ indicates the hydrogen atoms or the —NHCOR⁷ group (wherein, R⁷ indicates the phenyl with or without permutation atoms, the alkyl having 1-18 carbon atoms with or without permutation atoms and the cycloalkyl having 3-13 carbon atoms with or without permutation atoms.). Additionally, X indicates H, Na, K, Li or NH₄.

The charge control agent obtained from the method for producing the charge control agent is formed by the specific azo chromium complex indicated in the general formula (1). The charge control agent is the substance obtained from specific complex synthesis engineering, which is formed by a single azo chromium complex or the azo chromium complex with A^(m+) indicated more than 2 types of different cations in the general formula (1).

When the charge control agent of the invention is formed by the mixture of the azo chromium complex with more than 2 types of different counterions, excellent frictional electrification performance can be obtained; moreover, high dispersion can be obtained from the resin used by the toner, thus obtaining more excellent property.

Here, the reason why the charge control agent formed by the mixture of the azo chromium complex with more than 2 types of different counterions can obtain excellent property is still indefinite; but the reason can be presumed that: as the azo chromium complex gets mixed, the crystal structuring slows down and one-time particulate is easy to occur, and then the dispersion is improved.

In the synthesis engineering of the specific complex for synthesizing the specific azo chromium complex, the material azo compound and the complexing agent formed by the salicylic acid chromium complex is carried out complex formation reaction in the aqueous medium.

Here, the reaction resultant obtained from the complex formation reaction goes through counterion exchange treatment in acidic aqueous solution or inorganic aqueous ammonia according to necessities. Through the counterion exchange treatment, the counterions of the azo chromium complex which form the reaction resultant can be entirely transformed into other substances or used for preparing the mixture of the azo chromium complex with more than 2 types of different cations. Additionally, in the azo chromium complex with more than 2 types of different cations, the mixing ratio can be adjusted.

The material azo compound supplied to the specific complex synthesis engineering, i.e., the complex formation reaction can be dried substances or wet substances with larger proportion of water content. Generally, dried substances are adopted and the water content of lower than 5% is preferable.

The material azo compound supplied to the complex reaction can be properly selected according to the azo chromium complex required to be synthesized, for example, the aromatic compound indicated in the general formula (3) and the aromatic compound indicated in the general formula (4) are respectively diazotized by normal methods; the obtained aromatic diazo compounds are respectively coupled with the naphtholate compound indicated in the general formula (5) or the naphtholate compound indicated in the general formula (6) by normal methods, the compound indicated by the general formula (7) and the compound indicated by the general formula (8) can be obtained.

Here, in the coupling reaction of the aromatic diazo compound and the naphtholate compound for synthesizing the material azo compound, the commonly adopted reaction medium is the aqueous medium.

R¹ and R² respectively and independently indicate hydrogen atoms, alkyl having 1-18 carbon atoms with or without permutation groups, the alkenyl with 2-18 carbon atoms, the alkoxy with 1-18 carbon atoms, the sulfonic group, the Methyl sulfonyl, the sulfoacid amino, the alkyl amino sulfonyl with 1-18 carbon atoms, the hydroxyl, the carboxyl, the —COOR⁵ group (wherein, R⁵ indicates the alkyl with 1-18 carbon atoms), the acetylamino, the bromine atoms, the chlorine atoms, the iodine atoms, the fluorine atoms and the nitryl. n¹ and n² indicate integers between 0 to 4 (requiring to meet the condition of n¹+n²=4.).

R³ and R⁴ respectively and independently indicate hydrogen atoms, alkyl having 1-18 carbon atoms with or without permutation groups, the alkenyl with 2-18 carbon atoms, the alkoxy with 1-18 carbon atoms, the sulfonic group, the Methyl sulfonyl, the sulfoacid amino, the alkyl amino sulfonyl with 1-18 carbon atoms, the hydroxyl, the carboxyl, the —COOR⁵ group (wherein, R⁵ indicates the alkyl with 1-18 carbon atoms), the acetylamino, the bromine atoms, the chlorine atoms, the iodine atoms, the fluorine atoms and the nitryl. n³ and n⁴ indicate integers between 0 to 4 (requiring to meet the condition of n³+n⁴=4.).

In the formula, Z¹ indicates hydrogen atoms, carboxyl, hydroxyl, —COOR⁶ group (wherein, R⁶ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.), —CONHR⁷ (wherein, R⁷ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.), —NHCOR⁸ (wherein, R⁸ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.).

In the formula, Z² indicates hydrogen atoms, carboxyl, hydroxyl, —COOR⁶ group (wherein, R⁶ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.), —CONHR⁷ group (wherein, R⁷ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.), —NHCOR⁸ group (wherein, R⁸ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.).

In the formula, R¹ and R² respectively and independently indicate hydrogen atoms, the alkyl having 1-18 carbon atoms with or without permutation groups, the alkenyl with 2-18 carbon atoms, the alkoxy with 1-18 carbon atoms, sulfonic group, Methyl sulfonyl, sulfoacid amino, the alkyl amino sulfonyl with 1-18 carbon atoms, hydroxyl, carboxyl, —COOR⁵ group (wherein, R⁵ indicates the alkyl with 1-18 carbon atoms), acetylamino, bromine atoms, chlorine atoms, iodine atoms, fluorine atoms and nitryl. Z¹ indicates hydrogen atoms, carboxyl, hydroxyl, —COOR⁶ group (wherein, R⁶ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.), —CONHR⁷ group (wherein, R⁷ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.), and —NHCOR⁸ group (wherein, R⁸ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.); n¹ and n² indicate integers between 0 and 4 (requiring to meet the condition of n³+n⁴=4.).

In the formula, R³ and R⁴ respectively and independently indicate hydrogen atoms, the alkyl having 1-18 carbon atoms with or without permutation groups, the alkenyl with 2-18 carbon atoms, the alkoxy with 1-18 carbon atoms, sulfonic group, Methyl sulfonyl, sulfoacid amino, the alkyl amino sulfonyl with 1-18 carbon atoms, hydroxyl, carboxyl, —COOR⁵ group (wherein, R⁵ indicates the alkyl with 1-18 carbon atoms), acetylamino, bromine atoms, chlorine atoms, iodine atoms, fluorine atoms and nitryl. Z² indicates hydrogen atoms, carboxyl, hydroxyl, —COOR⁶ group (wherein, R⁶ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.), —CONHR⁷ (wherein, R⁷ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.), and —NHCOR⁸ (wherein, R⁸ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups.); n³ and n⁴ indicate integers between 0 and 4 ( requiring to meet the condition of n³+n⁴=4.).

Here, the specific examples of the compound indicated by the general formula (3) and the compound indicated by the general formula (4) are respectively: 4-chloro-2-amino phenol, 3,5-dichloro-2-amino phenol, 3,4,6-trichloro-2-amino phenol, 6-chloro-4-nitryl-2-amino phenol, 4,6-dinitro-2-amino phenol, 6-bromine-4-nitryl-2-amino phenol, 4-nitro phenol, 5-nitryl-2-amino phenol, 4-fluoride-2-amino phenol, 4-sulfonatyl-5-nitryl-2-amino phenol, 4-sulfamide-2-amino phenol, 4-methyl-2-amino phenol, 4,5-dimethyl-2-amino phenol, 5-methyl-4-nitryl-2-amino phenol, 4-octyl-2-amino phenol, 4-acetaldehyde amino-2-amino phenol, 2-amino phenol, 2-Aminothiophenol, aminobenzoic acid, 4-chloro-2-aminobenzoic acid, 5-chloro-2-aminobenzoic acid, etc.

Here, the specific examples of the compound indicated by the general formula (5) and the compound indicated by the general formula (6) are respectively: 2-naphthol, 2-hydroxyl-3-naphthoic acid, 2-naphthoic acid, 2-hydroxyl-3-methyl ester, 2-hydroxyl-3-(n)-butyl ester, 2-hydroxyl-3-octyl ester, 2-hydroxyl-3-octadecyl ester, 2-amino phenol, 2-monomethyl amidonaphthol, 2-thionaphthol, 3-hydroxyl-2-naphthanilide, 3-hydroxyl-4′-chloro-2-naphthanilide, 3-hydroxyl-2′,5′-dimethoxy-2-naphthanilide, 3-hydroxyl-3′-nitryl-2-naphthanilide, 3-hydroxyl-2′-methyl-4′-chloro-2-naphthanilide, 3-hydroxyl-2′,4′-dimethoxy-5′-chloro-2-naphthanilide, 3-hydroxyl-2-N-2′,6′-diisopropyl phenyl carbamyl-naphthalene, 3-hydroxyl-N-4′-octyl phenyl-naphthalene, 3-hydroxyl-2-N-propyl carbamyl-naphthalene, 3-hydroxyl-2-N-octyl carbamyl-naphthalene, 3-hydroxyl-2-N-dodecyl carbamyl-naphthalene, 3-hydroxyl-2-N-octadecyl carbamyl-naphthalene, 3-hydroxyl-2-N-octyloxy propyl carbamyl-naphthalene, 3-hydroxyl-2-N-cyclopropyl carbamyl-naphthalene, 3-hydroxyl-2-N-cyclohexyl carbamyl-naphthalene, 3-hydroxyl-2-N-cyclododecyl carbamyl-naphthalene, 2-hydroxyl-3-decoylamide-naphthalene, etc.

The complexing agent supplied to the complex formation reaction can adopt the salicylic acid chromium complex.

The salicylic acid chromium complex can be a chromium salicylic acid metal salt; the metal forming the chromium salicylic acid metal salt can adopt alkali metal salts composed of lithium salt, sodium salt and sylvite and alkaline earth metalloid salts composed of calcium salt and magnesium salt. From the point view of reactivity, the alkali metal salt is preferable.

Additionally, the salicylic acid section of the salicylic acid chromium complex can have permutation groups.

Here, the reason why the adoption of the chromium salicylic acid alkali metal salt which is used as the complexing agent improves the reactivity can be presumed that: the chromium salicylic acid alkali metal salt has excellent reactivity in the aqueous medium, thus easily carrying out complex exchange in the aqueous medium.

The application amount of the complexing agent supplied to the complex conformation reaction preferably excesses the excess quantity of the theoretic amount of the complete and definite complex reaction, specifically speaking, as far as 1 mol of material azo compound is concerned, 1.0-1.6 mol of complexing agent is preferable and more preferably 1.05-1.30 mol.

Additionally, in the complex formation reaction, the reaction medium is required to use the aqueous medium.

The components besides water, the principal component of the aqueous medium, can be used as the substances of the after mentioned strong polar solvent which is properly supplied to the complex formation reaction.

Specifically speaking, in the aqueous medium, as the principal component of the reaction medium used in the reaction for synthesizing the material azo compound by the coupling reaction of the aromatic diazo compound and the naphthol compound is water, the liquid component in the reaction solution obtained from the coupling reaction, which is also the material azo compound of the target reaction resultant obtained from the reaction solution of the coupling reaction, can be used as solidification component to be dispersed in dispersion liquid for proper use.

Additionally, the complex formation reaction is preferably carried out with the existence of the selected compounds from the group formed by long-chain alkyl ammonium salt, aryl ammonium salt and crown ether or strong polar solvents and inorganic base compounds.

As mentioned above, the complex formation reaction between the azo compound and the complexing agent is carried out with the existence of specific addition compound and inorganic base compound or the strong polar solvents and the inorganic base compound. In the complex formation reaction system, the combination of the specific addition compound or the strong polar solvents with the inorganic base compound can play the role of a reaction accelerator. The reaction accelerator enables the water and the organic substance to mutually take effect and results in smoother conduction of the complex formation reaction.

Additionally, the inorganic base compound selectively mixes with different compounds to be as the reaction resultant obtained from the complex formation reaction, thus obtaining the azo chromium complex mixture with more than 2 types of different counterions.

The specific addition compound is soluble substance in water or organic solvents; the specific addition compounds comprise the long-chain alkyl ammonium salts composed of tetrabutyl ammonium salt, trioctylphosphine methyl ammonium salt and benzyl dimethyl octadecyl ammonium salt, the aryl ammonium salts composed of alkylphenyl ammonium salt, and crown ether composed of 18-crown-6.

The specific addition compound can properly adopt long-chain alkyl or aryl ammonium salt.

The specific examples of the specific addition compounds have: (2-methoxyl ethoxy methyl)triethyl ammonium chloride, (3-acrylamide propyl)trimethyl ammonium chloride, (3-chloro-2-hydroxypropyl)trimethylammonium, acetylcholine chloride, benzoyl choline chloride, benzyl hexadecyl dimethyl ammonium chloride hydrate, benzyl dimethyl phenyl ammonium chloride, benzyl dimethyl stearoyl ammonium chloride hydrate, benzyltributyl ammonium chloride, benzyl triethyl ammonium chloride, benzoyl trimethyl ammonium chloride, choline chloride, dimethyl distearoyl ammonium chloride, DL-carnitine hydrochloride, dodecyl trimethyl ammonium chloride, hexadecatyl trimethyl ammonium chloride, hexa methonium chloride, methyl tri-n-octyl ammonium chloride, methyl triethyl ammonium chloride, n-decatyl trimethyl ammonium chloride, n-octyl trimethyl ammonium chloride, tetrabutyl ammonium chloride, trimethyl phenyl ammonium chloride, trimethyl stearoyl ammonium chloride, benzyl trimethyl ammonium bromide, decatyl trimethyl ammonium bromide, didecatyl dimethyl ammonium bromide, Dilauryl dimethyl ammonium bromide, hexadecatyl trimethyl ammonium bromide, n-octyl trimethyl ammonium bromide, phenyl trimethyl ammonium bromide, tetra-n-decatyl ammonium bromide, trimethyl stearoyl ammonium bromide, benzyl trimethyl ammonium hydroxide, etc.

Additionally, the application amount of the specific addition compound preferably adopts 1-30% by weight based on the amount of the salicylic acid chromium complex which is used as the complexing agent, and 5-20% by weight is more preferable.

The examples of the strong polar solvents have: N,N-dimethylformamide (DMF), N,N-dimethyl propanamide (DMA), N-methyl-2-pyrrolidinone, dimethylimidazolidine, dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), γ-butyrolactone, Diacetone Alcohol, etc.

Wherein, aprotic solvents composed of the N,N-dimethylformamide (DMF), the N,N-dimethyl propanamide (DMA), the dimethyl sulfoxide (DMSO) are preferable.

The application amount of the strong polar solvents preferably adopts 0.5-30% by weight based on the amount of the salicylic acid chromium complex which is used as the complexing agent, and 1-10% by weight is more preferable.

The inorganic base compounds can be any of inorganic alkali and inorganic weak base compound.

The inorganic alkali compounds comprise sodium hydroxide, potassium hydroxide, calvital, caustic baryta, etc.; the inorganic weak base compounds comprise sodium carbonate, sodium bicarbonate, ammonia, magnesium hydrate, cupric hydroxide, ferric hydroxide, etc.

When the inorganic base compounds adopt the inorganic alkali compound, the application amount is 0.5-30% by weight based on the amount of the salicylic acid chromium complex which is used as the complexing agent, and 1-10% by weight is more preferable.

On the other hand, when the inorganic base compounds adopt the inorganic weak base compound, the application amount is 1-30% by weight based on the amount of the salicylic acid chromium complex which is used as the complexing agent, and 2-15% by weight is more preferable.

The conditions of the complex formation reaction composed of the use of the specific addition compounds or the strong polar solvents and the inorganic base compounds have the reaction temperature of 100-160° C. and the reaction time of 2 to 15 hours.

In the complex formation reaction of the above methods for producing charge control agent, as the complexing agent adopts the salicylic acid chromium complex, the obtained reaction resultant not only has the azo chromium complex, but the part which actually does not react owning to the excessively added complexing agent that excesses the quantity of the chemical theory in the reaction system; as the high-proportion containing of the salicylic system chromium complex can bring bad influence to the electrification control performance, the containing proportion of the salicylic acid chromium complex needs to be reduced, for example, water and other ablutions are preferred to repeatedly carry out washing operation and other washing treatments for refining.

Additionally, in the charge control agent of the invention, in the occasions when the containing proportion of the salicylic acid chromium complex is 150-300 ppm (quality proportion), the electrification control performance of the azo chromium complex can be fully developed.

The washing treatment in the refining engineering can adopt the method called ‘centrifugal separation method’, specifically, the solidification part is separated and recycled from the reaction solution of the complex reaction through a centrifugal separation device and further dispersed in the water; after consisting with the water and fully dispersing and dissolving the impurity, the solidification part is further separated and recycled by the centrifugal separation device; the washing is repeatedly operated. Additionally, another method called ‘filter pressing’ is also available, specifically, the solidification part in the reaction solution of the complex reaction is separated and recycled by a filter pressing device and further dispersed in the water; after consisting with the water and fully dispersing and dissolving the impurity, the solidification part is further separated and recycled by the filter pressing device; the washing is repeatedly operated.

Either the centrifugal separation method or the filter pressing method is adopted to wash, when the ablution adopts tap water or well water, as the tap water or the well water contains various ions, the influence of the ions can cause the formic chromium and the chromium salicylic acid metal salt to have lower solubility to the water, the specific metal salt is hard to be effectively removed, and the problem of requiring larger amount of ablution for washing will occur; therefore, when the water is used as the ablution, ion exchange water is more preferable.

A method for producing the ion exchange water is not limited, the combination of ion exchange resin and high-accurate filter and active carbon is generally adopted, and the ion exchange water can be obtained from the tap water treatment engineering. The electric conductivity is preferably lower than 5 μS/cm and most preferably lower than 1 μS/cm.

The measurement method of the electrical conductivity is not particularly limited, for example, a conducting meter can be used for measuring.

Additionally, in the washing treatment, in the repeated washing operation, the electrical conductivity of the washing residual liquid obtained from the ultimate washing operation is preferably lower than 1000 μS/cm.

The electrical conductivity of the ablution can used for judging the removal degree of the conductive impurity containing the specific metal salts; when the electrical conductivity is lower than 1000 μS/cm, the amount of the impurity contained in the obtained charge control agent can be reduced to the expected proportion, therefore, the containing proportion of the specific metal salts in the charge control agent can be in the expected range.

When the electrical conductivity of the residual ablution is over high, the obtained charge control agent contains conductive impurity, namely, when the containing amount of the specific metal salts is over high. Therefore, in the toner containing the charge control agent, although the electrification performance is favorable, the leakage of the electrification is easy to occur and the problem of low absolute value of the charge can occur.

According to the method for producing charge control agent of the invention, the reaction system of the material azo compound and the compexing agent formed by the salicylic acid chromium complex for obtaining the specific azo chromium complex, the reaction medium can selectively adopt the aqueous medium; therefore, even the residual components of the reaction medium used by the synthesis engineering of the specific complex for synthesizing the specific azo chromium complex can not be completely removed, the disadvantages caused by the existence of the residual components of the reaction medium can be avoided.

In other words, in the well-known preparation methods, when the reaction medium in the complex formation reaction of the material azo compound and the complexing agent adopts ether system solvents such as ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, etc., as the ethylene glycol monoethyl ether and the ethylene glycol monomethyl ether are hazardous chemicals substances, the safety of the charge control agent is doubted; meanwhile, the disadvantages composed of unavailability of sufficient electrification performance can occur. In the method of the invention, the disadvantages will not occur.

Here, the reaction medium adopts ether system solvents such as ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, etc.; the reason why the residual components of the ether system solvents causes the charge control agent not to obtain sufficient electrification property can be presumed that: the ether system solvent with configurational energy is in a configurational state for the chromium which is the center metal of the azo chromium complex, thus bringing bad influence to the electrification property resulting from the center metal.

Additionally, in the obtained charge control agent, the water which is the principal component of the aqueous medium is existed as the residual component of the reaction medium, and the hydrogen in the water can generate charge generation energy, thus the property of the azo chromium complex can be played to obtain the charge control agent with excellent electrification control performance.

Furthermore, in the method for producing charge control agent, the reaction medium is the aqueous medium; the complexing agent is the salicylic acid chromium complex; the salicylic acid chromium complex is different from the formic chromium used in the prior as the complexing agent in that the salicylic acid chromium complex will not generate formic acid and other substances having harm to skin and human body, nor environment pollution and health problems.

Additionally, in the method for producing charge control agent, the material azo compound is used as the azo chromium complex; when the substances synthesized by the coupling reaction of the aromatic diazo compound and the naphthol compound are used, the reaction medium of the coupling reaction is the aqueous medium, the obtained reaction solution in the aqueous medium is formed by the dispersion of the azo compound of the target reaction resultant; therefore, the azo compound which is used as the target reaction resultant needs not to be recycled from the reaction solution; by adding the complexing agent into the reaction solution, the reaction system for synthesizing the zao chromium complex is formed and the charge control agent can be easily obtained.

Additionally, in the method for producing charge control agent, as the reaction of the azo compound and the complexing agent is carried out with the existence of the specific addition compound or strong polar solvent and inorganic base compound, when the complex formation reaction easily carries on, the selective use of the inorganic base compound can supply cations, that is, by means of using the mixture of different compounds, the reaction resultant obtained from the complex formation reaction can obtain the mixture of the azo chromium complex with more than 2 types of different counterions; through the formation of the mixture, the electrification property can be stabilized, thus easily producing the charge control agent with excellent electrification control performance.

The charge control agent obtained from the method for producing charge control agent of the invention can be greatly applied to the formation material of the toner which is used as the developer of the electrophotography, etc.

The toner of the invention contains the requisite charge control agent formed by the azo chromium complex; moreover, the components of the toner not only contain the requisite electric regulator, but also resins and colorants, or additives comprising a releasing agent and an external additive used as fixation improvers according to needs; furthermore, monochromic toners and color toners can also be used.

Here, the components of the toner of the invention are not limited besides the charge control agent; the well-known substances used in the past can be properly used.

Specifically speaking, the resin can be any kind of styrene acrylic resin, polyester resin, epoxide resin and other plastic resins, and the resins can be singly used or combined.

Additionally, the colorant can be any kind of carbon black, magnetite, pigments and dyes. The containing proportion of the colorant is 100 parts by weight based on the amount of the resin, preferably 0.5-10 parts by weight.

Additionally, the releasing agent can be any kind of the substances with low critical surface tension and low melting point, in particular to hydrocarbon such as low molecular weight polypropylene, low molecular weight polyethylene, Fischer-Tropsch wax, microcrystalline wax, paraffin wax and natural waxes such as long-chain carboxylic ethers of docosanoic acid stearyl alcohol ester, long-chain carboxylic ethers of pentaerythritol docosanoic acid ether, carnauba wax. The addition amount of the releasing agent is 100 parts by weight based on the amount of the resin, preferably 1-3% by weight.

The containing proportion of the charge control agent of the toner of the invention is 100 parts by weight based on the amount of the resin, preferably 0.1-10 parts by weight.

In the occasions when the containing proportion of the charge control agent is too low, the toner can not obtain sufficient electrification property; on the other hand, when the containing proportion of the charge control agent is too large, the electric conductivity of the charge control agent can occur charge leakage, and the toner can not obtain sufficient electrification; meanwhile, components of image formation devices such as a developing sleeve can be polluted, particularly when the toner is used as the formation material of the two-component developer; the pollution of carriers causes the toner not to obtain sufficient electrification property

The method for producing a toner is not limited; the generally adopted method can be the proper use of the existing methods such as smelt-blending pulverizing method and polymerization method.

The toner of the invention can be used both as a magnetic or nonmagnetic single-component developer and a two-component developer by blending with carriers.

When the toner is used as the magnetic single-component developer, a black colorant can properly adopt the magnetite, more ideally the magnetite with 80-200 nm of average particle size. The magnetite has various shapes such as cubic crystal shape, spherical shape and octahedron shape. If the toner is expected to turn red, the one with spherical shape is preferred. The addition amount of the colorant of the toner forming the magnetic single-component developer is different according to the developing method, while the addition amount in the occasions of non-contact imaging method is preferably 35-45% by weight based on the amount of the entire toner. In the occasion with over low addition amount, the flying of the toner may happen; on the other hand, in the occasions with over large addition amount, excellent developing performance is hard to get.

Additionally, when the toner is used as two-component developer, the colorant preferably adopts carbon black and the addition amount is preferably 5-10% by weight based on the amount of the entire toner; in order to control the chromatism, the toner can be combined with color pigments.

When the toner is used as the two-component developer, the carrier which is used for forming the two-component developer can be selected from metals such as iron, ferrate, magnetite and the existing metal materials such as the alloy of the metals and aluminum and lead; however, the ferrate is preferred, and more preferably light metal ferrate excluding copper, zinc, etc. while including alkali metals or alkali soil metals. Additionally, the carrier is preferably the carrier taking the metal materials as the core and having resins such as silicone, styrene acrylic resin, acrylic acid resin and fluorine-containing resin coating on the surface; the grain diameter of the carrier is that the volume based median diameter is preferably between 30 to 100 μm.

Advantages of the invention comprise: as the toner of the invention contains the charge control agent with excellent electrification control performance, even in the using environment with low temperature and low timidity, the image with stability and high picture quality can be obtained in a long time; additionally, when the image is formed in high printing speed, whether the toner is used as the single-component developer or two-component developer, excellent electrification property can be obtained; therefore, the flying of the toner or fog will not occur owing to uneven charge of the toner, thus acquiring the image with high picture quality.

BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION OF THE EMBODIMENTS

The following are the embodiments of the invention; however, the invention is not limited here.

EXAMPLE 1 FOR PRODUCING CHARGE CONTROL AGENT

At room temperature, 60 ml of water, 17 g of 37% hydrochloric acid and 15 g of 2-amino-4-irgasan are added into a three-neck flask with the volume of 250 ml and stirred for 0.5 hour to enable the 2-amino-4-irgasan to be dissolved in the hydrochloric acid; after the temperature of the aqueous solution is lowered to 5° C., 11 g of 35% NaNO₂ aqueous solution is added, the temperature is controlled to be lower than 5° C. and maintained between 0-5° C., the solution reacts for 2 hours and diazo salt solution is obtained.

On the other hand, 50 ml of water, 18 g of 25% NaNO aqueous solution and 8 g of 2-naphthol are added into a three-neck flask with the volume of 500 ml and stirred for 0.5 hour to obtain the naphthol solution with the 2-naphthol dissolved in the sodium hydroxide aqueous solution.

After the temperature of the obtained naphthol solution is lowered to 20° C., the diazo salt solution is instilled into the solution and the temperature is controlled to be lower than 25° C. Subsequently, the temperature of the system is controlled in the range of 20±5° C.; 5 hours later, the diazo salt of the 4-chloro-aminophenol is reacted with the 2-naphthol and suspension containing the azo compound is obtained from the reaction solution (which is called ‘material azo compound suspension (1)’ in the following.).

The obtained material azo compound suspension (1) is instilled with 95.5 g 10% salicylic acid chromium sodium aqueous solution which is used as the complexing agent; 1 g of specific addition compound benzyl triethyl ammonium chloride and 1 g of inorganic weak base compound are added; subsequently, the system temperature is raised to 100° C., the complex formation reaction is carried out for 10 hours at 100° C., and then the system temperature is reduced to 60° C.; the obtained reaction solution is filtered, the reaction resultant is recycled and washed by water to obtain a wet filter cake, and 17.5 g of charge control agent (which is called ‘charge control agent (1)’ in the following.) formed by the azo chromium complex as indicated in the chemical formula (A) can be obtained by drying at the temperature of 80° C.

EXAMPLE 2 FOR PRODUCING CHARGE CONTROL AGENT

Based on the embodiment 1, the obtained wet filter cake is added into the acidic aqueous solution formed by 125 g of water and 37% hydrochloric acid 11 g; the solution is conducted ion exchange treatment at the temperature of 55° C. for 1 hour, filtered, washed and dried at the temperature of 80° C., thus deriving 17.0 g of charge control agent (which is called ‘charge control agent (2)’.) formed by the mixture of 30% by weight of azo chromium complex as indicated in the chemical formula (A) and 70% by weight of azo chromium complex as indicated in the chemical formula (B).

EXAMPLE 3 FOR PRODUCING CHARGE CONTROL AGENT

At room temperature, 60 ml of water, 17 g of 37% hydrochloric acid and 11.6 g of 4,6-dinitryl-2-aminophenol are added into a three-neck flask with the volume of 250 ml and stirred for 0.5 hour; after the temperature of the aqueous solution is lowered to 5° C., the solution is cooled and the system temperature is controlled to be lower than 15° C.; meanwhile, 11 g of 35% concentration of NaNO2 aqueous solution is added; after 4 hours of heat insulation reaction at 10° C., diazo salt suspension can be obtained.

On the other hand, 50 ml of water, 18 g of 25% NaNO aqueous solution and 14.5 g of 3-hydroxyl-2-naphthamide are added into a three-neck flask with the volume of 500 ml and stirred for 0.5 hour to obtain the naphthamide solution with the 3-hydroxyl-2-naphthamide dissolved in the sodium hydroxide aqueous solution.

After the temperature of the obtained naphthamide solution is lowered to 20° C., the diazo salt suspension is instilled into the solution when the temperature is controlled to be lower than 30° C. Subsequently, the supply temperature is controlled in the range of 25±5° C. ; after 5 hours, the diazo salt of the 4,6-dinitryl-2-aminophenol is reacted with the 3-hydroxyl-2-naphthamide, the suspension containing the azo compound is obtained from the reaction solution (which is called ‘material azo compound suspension (2)’ in the following.).

The obtained material azo compound suspension (2) is instilled with 95.5 g of 10% salicylic acid chromium sodium aqueous solution which is used as the complexing agent; 5 ml of strong polar solvent N,N-dimethylformamide and 1 g of inorganic weak base compound are added; subsequently, after the system temperature is raised to 100° C., the complex formation reaction is carried out for 12 hours at 100° C., and then the system temperature is lowered to 60° C.; the obtained reaction solution is filtered, the reaction resultant is recycled and washed by water to obtain a wet filter cake, and 26.0 g of charge control agent (which is called ‘charge control agent (3)’ in the following.) formed by the azo chromium complex as indicated in the chemical formula (C) can be obtained by drying at the temperature of 80° C.

EXAMPLE 4 FOR PRODUCING CHARGE CONTROL AGENT

Based on the embodiment 3, the obtained wet filter cake is added into inorganic aqueous ammonia formed by 125 g of water, 26 g of ethanol and 19.5 g of ammonium chloride; after going through ion exchange treatment at the temperature of 80° C., the solution is filtered, washed by water and dried at the temperature of 90° C. then 25.5 g of charge control agent (which is called ‘charge control agent’ in the following) formed by the azo chromium complex as indicated in the chemical formula (D) can be obtained.

EXAMPLE 1 OF THE COMPARATIVE CHARGE CONTROL AGENT

15 g of 4-chloro-2-aminophenol are added into 180 g of water solution with 35 g of hydrochloric acid; when the temperature is lowered to 5° C., 22 g of sodium nitrite solution with concentration of 35% are added into the solution and react for 1 hour at the reaction temperature of 5° C. to obtain the reaction solution; the reaction solution is instilled into base solution combined by 15.1 g of 2-naphthol, 190 g of water and 8.5 g of sodium hydroxide (solid); at the temperature of 3° C., the reaction resultant can be obtained through coupling reaction. The obtained reaction resultant is separated, refined, washed and dried to obtain 30.4 g of azo compound (material azo compound (a) in the following). The obtained material azo compound (a) is fully used as a solvent to add into 74 g of ethylene glycol monoethyl ether, 11 g of formic acid chromium are added into the solvent in which the material azo compound (a) is added; after the complex formation reaction is carried out at the high reaction temperature of 130° C., the solution is separated and the reaction resultant is recycled to be dispersed in 5N hydrochloric acid, and the filter pressing device is used for separating the solidification part. Subsequently, the obtained solidification part is washed by water and dried at the temperature of 60° C., thus deriving 17 g of comparative charge control agent (which is called ‘comparative charge control agent (1)’ in the following) formed by the azo chromium complex as indicated in the chemical formula (A).

EXAMPLE 2 OF THE COMPARATIVE CHARGE CONTROL AGENT

Based on the comparative example 1, the preparation process is the same as in comparative example 1, the only difference is 11 g of formic acid chromium is replaced by 17.5 g of chromium sodium salicylate and the reaction temperature of the complex formation reaction is changed into 125° C., then comparative charge control agent (which is called ‘comparative charge control agent (2)’ in the following) formed by the azo chromium complex as indicated in the chemical formula (A) is obtained.

EXAMPLE 3 OF THE COMPARATIVE CHARGE CONTROL AGENT

Based on the comparative example 1, the preparation process is the same as in comparative example 1, the only difference is 11 g of formic chromium which is used as the complexing agent is replaced by 19 g of lactic chromium and the ethylene glycol monoethyl ether which is used as the reaction medium is replaced by ethylene glycol monomethyl ether. The charge control agent (which is called ‘comparative charge control agent (3)’ in the following.) as indicated in the chemical formula (A) is obtained.

The charge control agents respectively obtained from the embodiments 1-4 and the comparative embodiments 1-3 are used for producing the toner according to the following methods and the toner is further used for producing the two-component developer.

First, 1 part by weight of the charge control agent, 100 parts by weight of the styrene acrylic resin (styrene:butyl acrylate:methyl methacrylate=70:20:5 (mass portion), softening point is 128° C.), 8 parts by weight of carbon black ‘MOGUL L’ (made by the cabot company) and 6 parts by weight of low molecular weight polypropylene ‘660P’ (made by Sanyo formation industry) are mixed in a Henschel mixer; the obtained mixture is melted, blended and cooled by a two-axis extruder, pulverized by a fluid jet mill, classified by a spin-flow classifier, thus obtaining the coloring particles with 8.5 μm of volume based median diameter.

Subsequently, 100 parts by weight of the obtained coloring particles are added with 0.8 parts by weight of hydrophobic silica with 12 nm of average particle size and 67th of hydrophobization degree and mixed by the Henschel mixer to obtain the toner.

In the following, the toners adopting the charge control agent (1) to the charge control agent (4) are respectively called toner (1) to toner (4); additionally, the toners adopting comparative charge control agent (1) to comparative charge control agent (3) are respectively called comparative toner(1) to comparative toner (3).

The obtained toners are mixed with the carrier formed by the light metal ferrite covered with silicone with 65 μm of volume average grain diameter to obtain the two-component developer with 8% concentration of toner.

In the following, the two-component developers adopting toner (1) to toner (4) are respectively called developer (1) to developer (4); additionally, the two-component developers adopting comparative toner (1) to comparative toner (3) are respectively called comparative developer (1) to comparative developer (3).

Thus, the developer (1) to developer (4) and the comparative developer (1) to comparative developer (3) are obtained. The following methods are adopted to evaluate the electrification property and the picture quality of the image. The results are shown in the chart 1.

(1) Electrification Property

1 g of toner which forms the developer (1) to the developer (4) and the comparative developer (1) to the comparative developer (3) and 10 g of carrier are respectively weighted and added into a glass tube with 20 ml of volume; in the low-temperature environment (the low temperature is 10° C. and the humidity is 10% RH), after a YAYOI typed (YAYOI is the company name) vibration machine is used for stirring for 1 minute, 2 minutes, 5 minutes, 10 minutes,20 minutes and 60 minutes respectively, and an charge measuring device ‘TB-200’ (manufactured by Toshiba Company) is used for measuring the charge in normal-temperature and normal-humidity environment.

(2) The Picture Quality of the Image

The developer (1) to the developer (4) and the comparative developer (1) to the comparative developer (4) are respectively used in a contact imaging method, a duplicator which can form the image at a speed of 120 pieces per minutes is used for printing the image in A4 sized paper with a coverage rate of 5% in a low-temperature and normal-humidity environment (the temperature is 10° C. and the humidity is 50% RH); after the 50 pieces of A4 sized copying paper are used for forming images in succession, the image formation mode of pausing 1 minute for the image formation action is adopted to form images in 500 thousand pieces of copying paper. The concentration of the all-black images and concentration of the fog of the white ground part in the initial-stage image formed after the primary image formation action (indicated by ‘initial stage’ in the chart 2) and the image formed in the No. 500 thousand time (indicated by ‘500,000th piece’ in the chart 2) are respectively measured by the ‘RD-918’ of the Macbeth Company. When measuring, the reflection concentration of the copying paper is 0, and the opposite reflection concentration us measured.

Additionally, the resolution of the characters in the primary image and the 500 thousand one is visually measured and the charge of the toners are respectively measured after the primary image and the 500,0000th are formed.

CHART 1 Serial Electric numbers charge Charge (-μC/g) of the regulator 1 2 5 10 20 60 toner (CCA) minute minute minute minute minute minute Developer 1 1 1 21.1 21.2 21.2 21.2 21.2 21.2 Developer 2 2 2 21.3 21.4 21.4 21.4 21.4 21.4 Developer 3 3 3 21.5 21.7 21.7 21.7 21.7 21.7 Developer 4 4 4 21.8 21.9 21.9 21.9 21.9 21.9 Comparative Comparative Comparative 15.3 16.8 21.0 21.4 21.7 21.9 developer 1 toner 1 CCA 1 Comparative Comparative Comparative 15.2 16.7 20.8 21.6 21.9 22.1 developer 2 toner 2 CCA 2 Comparative Comparative Comparative 15.3 16.4 20.8 21.6 22.1 22.2 developer 3 toner 3 CCA 3

CHART 2 Evaluation Image density Fog density Resolution Charge Serial Charge (%) (%) (/mm) (-μC/g) numbers control The The The The of the agent Initial 500,000th Initial 500,000th Initial 500,000th Initial 500,000th toner (CCA) stage piece stage piece stage piece stage piece Developer 1 1 1 1.42 1.42 0.000 0.000 6 6 22.4 20.9 Developer 2 2 2 1.43 1.42 0.000 0.001 6 6 22.3 21.0 Developer 3 3 3 1.43 1.43 0.000 0.001 6 6 22.1 21.3 Developer 4 4 4 1.43 1.44 0.000 0.000 6 6 22.2 21.7 Comparative Comparative Comparative 1.29 1.33 0.004 0.010 5 4 17.3 20.1 Developer 1 toner 1 CCA 1 Comparative Comparative Comparative 1.28 1.32 0.003 0.010 5 4 16.9 20.3 Developer 2 toner 2 CCA 2 Comparative Comparative Comparative 1.28 1.33 0.004 0.011 5 4 17.1 20.1 Developer 3 toner 3 CCA 3

According to the results of the chart 1 and the chart 2, when the toner in the embodiment 1 to the embodiment 4 containing the charge control agent formed by the azo chromium complex synthesized in the aqueous medium is used as the developer, even in the low-temperature environment, excellent electrification property can be obtained and the image with high picture quality in a long time can be stably obtained.

On the other hand, in the occasions of using the toner in comparative example 1 to comparative example 3 as the developer, the azo chromium complex which forms the charge control agent is not synthesized in the aqueous medium but in the organic solvent; therefore, the electrification of the toner takes a long time and stable and durable charge can not be obtained, thus failing to stably obtain the image with high picture quality in a long time.

This invention is not to be limited to the specific embodiments disclosed herein and modifications for various applications and other embodiments are intended to be included within the scope of the appended claims. While this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims. 

1. A method for producing charge control agent formed by the azo chromium complex is characterized in that, in the aqueous medium, the reaction of the azo compound and the salicylic acid chromium complex which is used as the complexing agent synthesize the azo chromium complex indicated in the general formula (1),

wherein, R¹ to R⁴ respectively and independently indicate hydrogen atom, the alkyl having 1-18 carbon atoms with or without permutation groups, the alkenyl with 1-18 carbon atoms, the alkoxy with 1-18 carbon atoms, sulfonic group, Methyl sulfonyl, sulfoacid amino, the alkyl amino sulfonyl of the alkyl with 1-18 carbon atoms, hydroxyl, carboxyl, —COOR⁵ group, in which, R⁵ indicates the alkyl with 1-18 carbon atoms, acetylamino, bromine atoms, chlorine atoms, iodine atoms, fluorine atoms and nitryl. Z¹ and Z² respectively and independently indicate hydrogen atoms, carboxyl, hydroxyl, —COOR⁶ group, wherein, R⁶ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups, —CONHR⁷, wherein, R⁷ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups, and —NHCOR⁸, in which, R⁸ indicates the phenyl with or without permutation groups, the alkyl having 1-18 carbon atoms with or without permutation groups, the cycloalkyl having 3-12 carbon atoms with or without permutation groups; additionally, A^(m+) indicates the cations with 1-6 valents; m indicates an integer between 1 and 6, n¹-n⁴ indicate integers between 0 and 4 and are required to meet the condition of n¹+n²=4 and n¹+n²=4.
 2. The method for producing charge control agent of claim 1 is characterized in that the salicylic acid chromium complex which is used as the complexing agent is chromium salicylic acid alkali metal salt.
 3. The method for producing charge control agent of claim 1 is characterized in that the reaction between the azo compound and the salicylic acid chromium complex which is used as the complexing agent is carried out with the existence of the selected compounds from the group formed by long-chain alkyl ammonium salt, aryl ammonium salt and crown ether or strong polar solvents and inorganic base compounds.
 4. The method for producing charge control agent of claim 2 is characterized in that the reaction between the azo compound and the salicylic acid chromium complex which is used as the complexing agent is carried out with the existence of the selected compounds from the group formed by long-chain alkyl ammonium salt, aryl ammonium salt and crown ether or strong polar solvents and inorganic base compounds.
 5. The method for producing charge control agent of claim 1 is characterized in that the azo compound is obtained from the coupling reaction and synthesis of the aromatic diazo compound and the naphthol compound, and the salicylic acid chromium complex is added into the reaction solution obtained from the coupling reaction as the complexing agent.
 6. The method for producing charge control agent of claim 2 is characterized in that the azo compound is obtained from the coupling reaction and synthesis of the aromatic diazo compound and the naphthol compound, and the salicylic acid chromium complex is added into the reaction solution obtained from the coupling reaction as the complexing agent.
 7. A toner is characterized in that the toner includes the charge control agent obtained from the method for producing charge control agent of claims
 1. 8. A toner is characterized in that the toner includes the charge control agent obtained from the method for producing charge control agent of claims
 2. 9. A toner is characterized in that the toner includes the charge control agent obtained from the method for producing charge control agent of claims
 3. 10. A toner is characterized in that the toner includes the charge control agent obtained from the method for producing charge control agent of claims
 4. 11. A toner is characterized in that the toner includes the charge control agent obtained from the method for producing charge control agent of claims
 5. 12. A toner is characterized in that the toner includes the charge control agent obtained from the method for producing charge control agent of claims 6.6-dinitryl- 